Conventionally, there is known a so-called traction planetary gear mechanism as this type of the continuously variable transmission. The traction planetary gear mechanism has a transmission shaft acting as a center of rotation, plural rotating elements capable of relatively rotating using a central axis of the transmission shaft as a first rotation central axis, and second rotation central axes separate from and parallel with the first rotation central axis and includes plural rolling members radially disposed about the first rotation central axis, support shafts for causing the rolling members to rotate on their axes as well as supporting the rolling members, and a fixed element fixed to the transmission shaft and holding the rolling members via respective projecting sections from the rolling members in the support shafts. In the traction planetary gear mechanism, the respective rolling members are between the first rotating element and the second rotating element disposed in confrontation with each other as well as the respective rolling members are disposed on an outer circumferential surface of a third rotating element, and a transmission ratio is continuously variably changed by tilting the rolling members.
For example, Patent Literature 1 described below discloses this type of a continuously variable transmission. In the continuously variable transmission, an input shaft of torque (power) is coupled with any one of first and second ring members as the first and second rotating elements, and an output shaft of torque is coupled with the other thereof. Then, the input shaft and the output shaft are disposed so as to relatively rotate about a first rotation central axis via a bearing disposed between the input shaft and the output shaft. The input shaft and the output shaft have disk sections confronting with each other. The disk section of the input shaft is thinner than the disk section of the output shaft. For example, the input shaft and the output shaft relatively rotate via a roller bearing disposed on an outside diameter side between the respective disk sections and a ball bearing disposed on an inside diameter side between the respective disk sections. The roller bearing is disposed for a purpose of reducing drag torque and abuts respective races to plane portions of the respective disk sections disposed in parallel with each other.
This type of the continuously variable transmission is disclosed also in Patent Literature 2 described below. The continuously variable transmission of Patent Literature 2 also includes an input shaft and an output shaft, and a roller bearing on an outside diameter side and a ball bearing on an inside diameter side (inner circumferential surface side) are disposed between respective disk sections likewise Patent Literature 1. Note that, also in the continuously variable transmission of Patent Literature 2, although respective races of the roller bearing are abutted to plane portions of respective disk sections disposed in parallel with each other, an inside diameter side of the disk section of the output shaft is tilted more than the roller bearing.